-----Original Message-----
From: Javier Martinez Canillas [mailto:martinez.javier at gmail.com]
Sent: Friday, December 16, 2011 6:04 PM
To: Jeff Haran
Cc: Alexandre Courbot; Jimmy Pan; Kernelnewbies at kernelnewbies.org
Subject: Re: Is there a way to build a cross reference with kernel file

On Sat, Dec 17, 2011 at 1:58 AM, Jeff Haran [off-list ref]
wrote:

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-----Original Message-----
From: kernelnewbies-bounces at kernelnewbies.org

[mailto:kernelnewbies-

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bounces at kernelnewbies.org] On Behalf Of Alexandre Courbot
Sent: Monday, October 24, 2011 7:05 PM
To: Jimmy Pan
Cc: Kernelnewbies at kernelnewbies.org
Subject: Re: Is there a way to build a cross reference with kernel

file

quoted

On Tue, Oct 25, 2011 at 12:00 AM, Jimmy Pan [off-list ref]

wrote:

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It seems we can use ctags, while, I don't really know how to

implement it.

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I don't want to use the online cross reference every time...

I personally use KDevelop to navigate the kernel. It's not perfect yet
and a little bit tricky to configure correctly, but it's still pretty
efficient and I work on improving it. I wrote about it recently:
http://www.gnurou.org/code/kdevelop-kernel

CTags is also known to work well, actually there is even a 'make tags'
target in the kernel's Makefile.

Hope this helps,
Alex.

...

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Has anybody found a tool the solves this kind of problem well?
Specifically, given a struct foo containing a field named bar, show me
all of the code that references the bar field of struct foos but not the
bar fields of other structures nor instances of variables that are
themselves named bar.

I realize that with things like arbitrary type casting and the C
pre-processor, doing this kind of thing with 100% accuracy could be
quite difficult. But even if it was only partially successful at
eliminating the false positives that come with tools like cscope, it
could save a lot of time.

Well you can always rely on conventions. For the sk_buff example,
generally the kernel uses sk_buff pointers and the variable name is
almost always skb. So git grep skb->cb is a good approach to this.

Problem is one can't count on these conventions being followed. There are pointers to struct sk_buffs that aren't named skb (for example, struct sk_buff *skbuff and struct sk_buff *skb2 appear in several places) so by assuming they are all named skb will mean you miss some that might be important.

... 

Again, ETAGS and tools like that are good for pointing where a symbol
is defined, but its usage is a little more trickier. Like you said the
kernel uses _lots_ of functions pointers so I don't think that a tool
that shows me every place a given function is called will be easier
(if possible) to implement.

Yes, that's another problem. And agreed, something like this would likely be difficult to put together given the way C works.

Hope it helps,

--
Javier Mart?nez Canillas
(+34) 682 39 81 69
Barcelona, Spain

Well, it helps in the sense that I think it answers my question. No such tool seems to exist.

Thanks,

Jeff Haran